Field of the Invention:
The invention in general relates to viewing systems, and more particularly to a TV viewing system in an underwater environment or other medium subject to backscatter.
Description of the Prior Art:
For viewing targets in a backscatter medium, such as in underwater viewing, extensive use is made of television cameras. In the conventional floodlit underwater imaging system, it is well known that the contrast obtained is limited because the camera must view the scene through a veiling irradiance produced by the scattering volume formed by the intersection of the light beam and the TV camera field of view.
In performing studies such as biological and geological surveys, the viewing apparatus on a carrier vehicle moves over the target area terrain along a course line and very often backscatter problems make target identification extremely difficult, if not impossible. Backscatter can be reduced by minimizing the mutual volume between the light and the camera field of view and several techniques propose the use of mechanical scanning devices. These mechanical devices, however, are often difficult to implement and suffer from synchronizing problems.
The present invention provides a viewing system wherein the effects of backscatter are significantly reduced without the requirement of mechanical scanning of a light beam or scanning camera aperture.